Transarterial embolization in osteoarthritis of the knee: Mechanism of action and current results

BACKGROUND: Approximately 5.2 million people in Germany suffer from osteoarthritis of the knee. Minimally invasive embolization of the genicular artery (GAE) was first described in 2015. It reduces pathologically altered synovial vascularization in the periarticular tissue and the associated inflammatory processes. It is thought that this can inhibit the disease process and relieve pain in patients with symptomatic osteoarthritis of the knee who do not respond to conservative treatment. In this review, we assess this technique with regard to its safety and efficacy. METHODS: This narrative review is based on pertinent publications (2015-2025) retrieved by a search in the PubMed/Medline and Google Scholar databases for prospective and retrospective clinical studies and meta-analyses. RESULTS: 25 studies on GAE have appeared since 2015, among them three randomized controlled trials (RCTs) with sham controls (n = 21; n = 59; n = 58). In a small-scale multicenter RCT (n = 21), GAE reduced pain to a markedly greater extent at 1 month compared to controls (VAS difference 50.1 mm, 95% confidence interval [29.0-72.3]; p < 0.01). Two larger RCTs did not reveal any significant additional benefit compared to sham treatment. In the Australian triple-blind RCT (n = 59) the mean improvement in the KOOS pain score at 12 months was higher in the GAE group (41.3% vs 29.4%), but the difference between groups was not significant. In the Dutch RCT (n = 58), the mean improvement in the KOOS pain score at 4 months was 21.4 points [13.9-28.8] after GAE and 18.4 [11.6-25.1] after sham treatment; the intergroup difference of 3 points was not significant ([-7.1 to 13.0], p = 0.31). Adverse events were rare and generally self-limiting. CONCLUSION: Before-and-after studies showed safe pain relief by GAE, but these findings have not been confirmed by the RCTs that have been carried out to date. Current evidence is mixed. Larger-scale, methodologically robust RCTs are needed so that the efficacy of GAE and its role in the treatment of symptomatic knee osteoarthritis can be reliably evaluated.